/**
 * 将完整 HTML 邮件转为适合 div[v-html] 的片段：
 * 取 body.innerHTML，并前置 head 内 <style>，避免版式与改版前不一致。
 */
export function normalizeEmailHtmlForInlineDisplay(html) {
    if (!html || typeof html !== 'string') return '';
    const t = html.trim();
    if (!/^<!DOCTYPE|^<\s*html[\s>]/i.test(t)) return html;
    try {
        const doc = new DOMParser().parseFromString(html, 'text/html');
        const body = doc && doc.body;
        if (!body) return html;
        const inner = body.innerHTML;
        if (!inner || !inner.trim()) return html;
        let headInject = '';
        const head = doc.head;
        if (head) {
            head.querySelectorAll('style').forEach((node) => {
                headInject += node.outerHTML;
            });
        }
        return headInject + inner;
    } catch (e) {
        return html;
    }
}